I went through most of the vetting at an AOPA fly-in a bunch of years ago, when they first dreamed this foolishness up, then eventually got to DCA for my fingerprinting (though, why the local cop shop couldn't have done as well I don't know) and waited months for my PIN. Finally chased it down, flew to Hyde Field, Clinton MD a couple of times, and then decided to try College Park, as it's far more convenient to my destination. It was quite a seamless operation- Called Leesburg's dedicated FRZ line, the guy who answered identified himself as Raleigh FSS, told them I was associated with W32, but wished to fly into College Park. I gave him my PIN, filed my flight plan via my best guess by airways avoiding DC itself, picked up a 'direct EDE- CGS' clearance on the ground. Just a bit north of Richmond, I was cleared to PXT, direct WHINO, direct MITCH and then radar vectors, but the whole reroute didn't add much more than 10 minutes to the trip. Cancelled IFR five miles from CGS, landed there without any problem, found the staff there to be lovely, no escort required. They provided the prop lock, and got me on my way with excellent promptness. On the way out, the ride from midDC took 20 minutes on the Green Line. I'll do that trip again without hesitation, especially since the world's cutest granddaughter is only five subway stops south of College Park. Flying IFR, in particular, is quite easy: somebody holds your hand the whole way.